1. Field of the Invention
The present invention relates to a mobile apparatus, and particularly to a mobile apparatus with an antenna of a grounding part having double ground terminals.
2. Description of Related Art
Currently, communication methods of the public are gradually changed to wireless communications, and wireless communication devices become more diversified, for example, smart phones, multimedia players, personal digital assistants (PDA), satellite navigation devices and so on. Owing to current handheld 3 G communication devices, for example, mobile phones, designed in a way towards a trend of light weight, slimness, tiny and compact size, antenna design on the other hand also requires improvements and updates different from traditional ways of the antenna design.
Currently, there are two general and common ways of the antenna design for wireless communication devices in the market. One is a planar inverted F antenna (PIFA) as illustrated in FIG. 1A and FIG. 1B, and the other is a monopole antenna as illustrated in FIG. 2A and FIG. 2B. Referring to FIG. 1A and FIG. 1B, the PIFA 100 includes, in addition to a body part 100, also a feeding part 120 and a grounding part 130, wherein the grounding part 130 requires to be electrically connected to a ground plane, and the design of the PIFA 100 mainly acquires a plurality of required resonance frequencies through two current paths with different lengths. On the other and, referring to FIG. 2A and FIG. 2B, the design of a monopole antenna 210 requires a clearance area 220 on surroundings of the monopole antenna 210 in order to prevent electronic components too close to the monopole antenna 210 from interfering to antenna performance.
It is to be noted that, conventional PIFAs mainly have advantages of easy design for miniaturization, and a specific absorption ratio (SAR) is smaller for use of the antenna of the mobile apparatus. However, if the PIFA is disposed internally inside the mobile apparatus, a height of the antenna is limited due to adaptation of the design for miniaturization, also meaning a limitation of a spacing distance between the body part and the ground plane such that the PIFA has disadvantages of smaller bandwidth and lower antenna gain. Therefore, for the PIFA, a tradeoff of the height and the bandwidth of the antenna is a major challenge in the design for the antenna.